Bioinstructive Hybrid Scaffold Integrating Phosphoinositide 3-Kinase-Akt and Complementary Survival Pathways for Kidney Regeneration.

Abstract

Chronic kidney disease (CKD) is a major clinical challenge because it leads to irreversible nephron loss and limited endogenous repair. Here, we developed a bioactive hybrid scaffold composed of PLGA, magnesium hydroxide (MH), extracellular matrix (ECM) components, zinc oxide, lactoferrin, and nicotinamide loaded liposome (LNP) and extracellular vesicles (EVs) hybrid nanoparticles (hEV) complexes (PMEZL/hEV) to promote renal repair by integrating PI3K-AKT signaling with complementary pro-survival pathways. In a 5/6 nephrectomy model, scaffold implantation significantly attenuated inflammation and oxidative stress. qPCR analyses showed suppressed NF-κB and TNF-α levels with increased expression of Nephrin, Podocin, IL-4, IL-10, SOD, and Sirt-1 at 2 weeks, which became further pronounced at 8 weeks in the PMEZL/hEV group. Western blot analysis demonstrated marked activation of p-AKT and lower levels of caspase 9 and cleaved caspase 3, indicating inhibition of apoptotic signaling. Importantly, cytoprotective effects were partially preserved under PI3K-AKT inhibition, suggesting engagement of complementary PI3K-AKT independent survival mechanisms. Concurrent downregulation of PAI-1 suggested suppression of fibrotic remodeling. Immunohistochemistry confirmed progressive restoration of Synaptopodin and PAX2, supporting podocyte recovery and tubular regeneration. Histological analyses revealed decreased fibrosis and increased glomerular density across scaffold implanted groups, with the greatest improvements in kidneys implanted with the PMEZL/hEV scaffold. Functional measurements showed a reduction in serum blood urea nitrogen (BUN), creatinine, C-reactive protein, and cystatin C, with significant improvements by 8 weeks. Collectively, the multifunctional hybrid scaffold orchestrates anti-inflammatory, antioxidative, antiapoptotic, and pro-regenerative responses through coordinated multimodal survival signaling, leading to substantial restoration of kidney structure and function in CKD.